In brutal, cold-weather playoff football — and the Jets’ AFC Championship game tomorrow at Pittsburgh promises to be just that — the games are decided in the trenches.

Nick Mangold will be at the center of that, figuratively and literally, when he goes up against Pro Bowl nose tackle Casey Hampton.

With his scruffy beard and let-it-be hair, Mangold has the look of a lumberjack. Felling Hampton, who appears far heavier than his listed 6-foot-1, 325-pound dimensions, may well prove to be his toughest task yet. But, naturally, always-confident Jets coach Rex Ryan claims his center is up to the job.

“The good thing is Nick Mangold faces [great tack les] in our division,” Ryan said yesterday. “You’ve got all those 3-4 teams anyway. You’ve got New England with big Vince Wilfork. You’ve got Miami that plays a 3-4. So he’s played against some excellent players.

“And he’s played against Casey Hampton before. So clearly there is a reason why he’s a Pro Bowl nose tackle, but there is also a rea son why Nick Man gold is the Pro Bowl center.”

Mangold has been hardened by facing not only the Pat riots’ Wilfork, also seemingly bulkier than his listed 325 pound weight, but by practicing against the likes of Kris Jenkins until Jenkins suffered a season-ending knee injury in the opening loss to Baltimore.

Mangold held Hampton to a quiet three tackles in the Jets’ 22-17 win at Pittsburgh on Dec. 19. And after getting the best of Wilfork in last weekend’s duel — helping the Jets’ offensive line get through the AFC divisional upset in New England without giving up a single sack — Mangold is hoping to do the same in his rematch with Hampton.

“It really gets no easier each week, going from Vince to Casey,” Mangold said. “Casey does just a fantastic job with his technique. Obviously his size and strength, you can see that, but the way that he plays with his hands, his leverage, gets under guys, it’s pretty impressive.”

The same could be said of the entire Steelers defense, which Hampton is at the heart of. Pittsburgh finished the regular season allowing just 62.8 rushing yards per game, a mark bettered just four times in NFL history — two of those during World War II.

That’s the kind of impenetrable 3-4 defense that Mangold will try to open holes in for Shonn Greene and company.

“It’s a tough road, and it’s going to be a hard battle to get through,” Mangold said. “It’s just an exciting time. Everybody realizes the task at hand, realizes our goal wasn’t to get back to the AFC championship, it’s to go to the Super Bowl. That’s the big focus, and they understand what they need to get done.”